annealing metal

Materials and Equipment
Annealing Physics
See attached pages on metalurgy
(from "The Complete Metalsmith", revised edition, by Tim McCreight, copyright 1991 Davis Publications, Inc., Worchester, MA)
Procedure
  1. Determine what metal you are using and check the procedure for annealing it.
  2. Turn on ventilation.
  3. Turn on pickle pots, and gather tools.
  4. Turn main gas valve to open position (the valve handle will be aligned with the pipe).
  5. Lay the metal to be annealed in the annealing pan, and flux it if it is indicated for the metal you are using.
  6. Turn the gas and air valves to the open position (the valve handle will be aligned with the hoses).
  7. Hold the striker in the palm of your hand and push the side attached to the flint down and across the steel. Spark striker a few times to practice, and to check the flint.
  8. Open gas valve on torch handle (the side attached to the red hose) 1/2 turn.
  9. Immediately light torch by holding cup of striker under the nozzle, cup pointing up, and sparking the striker. (natural gas is heavier than air and will sink to fill the cup of the striker)
  10. Once the gas is lit, increase the flow until a large bushy flame is achieved. PAY ATTENTION TO WHERE YOU POINT IT!
  11. Slowly add a small amount of compressed air to give the flame force and direction.
  12. Hold the torch so that the flame is pointed straight down at the metal, far enough away from the metal so that the widest part of the flame is covering as much of the the metal's surface as possible. Keep the flame moving across entire surface. This is important as the goal is to bring the whole piece up to temperature at the same time.
  13. Continue heating until the metal reaches the desired temperature.
  14. If indicated for the metal you are annealing, quench the metal by picking it up with the copper tongs and quickly plunging it into the quenching pan. The metal should be quenched all at once if possible.
  15. Turn off the torch; air first, and gas last.
  16. If quenching is not indicated for the metal you are using remove the metal from the annealing pan, set it somewhere where no-one will accidentally touch it and let it air cool.
  17. Pickle and scrub the metal to remove the accumulated oxides.
  18. Turn off all gas and air valves.
  19. Turn off ventilation.
Metal-specific Procedures:
Metal annealing & melting points procedure quench or air cool?
Aluminum

640-670°F / 1220°F

smear with liquid soap and heat until the soap turn brownish-black quench but do not pickle
Brasses

800-1450°F / 1660°F

heat until dark oxides form when torch is removed air cool
Bronze 800-1450°F / 2250°F heat until dark oxides form when torch is removed quench
Copper 950°F / 1981°F heat until dark oxides form when torch is removed quench
Gold (fine) X / 1945°F no annealing is needed n/a
Nickel silver 1100-1500°F / 1960°F coat metal in flux and heat until flux matures air cool
Niobium 2100-3200°F / 4474°F must be annealed in a vacuum n/a
Silver (fine)

572°F / 1761°F

heat in dark room until first flush of pink appears, or coat metal in flux and heat until flux matures air cool 10 seconds, then quench
Sterling silver 1200°F / 1640°F coat metal in flux and heat until flux matures air cool 10 seconds, then quench
Titanium 1100-1350°F / 3272°F must be annealed in a vacuum n/a

 

Safety Precautions: